matchExpressions is a list of label selector requirements. The requirements are ANDed.
key
string required
key is the label key that the selector applies to.
operator
string required
operator represents a key's relationship to a set of values.
Valid operators are In, NotIn, Exists and DoesNotExist.
values
[]string
values is an array of string values. If the operator is In or NotIn,
the values array must be non-empty. If the operator is Exists or DoesNotExist,
the values array must be empty. This array is replaced during a strategic
merge patch.